如何从Enumerable.Any和List.Contains中获取字符串值包含比较？

Question

I have 2 string lists that I am checking if List 1 contains any of the items in List 2.

if (List2.Any(s => List1.Contains(s)))
{ //do stuff 
}

If a string is found, I am wanting to log it, but I cannot find a way to get the value of S from the above code.

When I try to write out 'S' as a variable for a string, it isn't recognized as one.

How can I get the value of S from my above comparison?

Also - I couldn't figure out how to put into words specifically what I was after for the title. If you have a recommendation on how to re-write the Title, I'm open to it. I'd like it to be accurate for the question.

Answer 1

Enumerable.Any isn't meant to get what's being found but just that something was found .

If you also want what was found , I believe you should use Enumerable.FirstOrDefault :

string result = list2.FirstOrDefault(s => list1.Contains(s));

if(!string.IsNullOrEmpty(result))
{
    // do stuff...
}

In the other hand, if you want all coincidences, you should use Enumerable.Intersect :

IEnumerable<string> allCoincidences = list2.Intersect(list1);

Answer 2

This Linq will do what you need in just one line

if ((from s in List2 from s1 in List1 where s == s1 select s).Any())
{
  //do stuff 
}